准分子激光屈光性角膜术(LASIK和LASEK)对泪膜稳定性及角膜中央知觉的影响?

目的:观察准分子激光角膜原位磨镶术(laser in situ keratomileusis,LASIK)和准分子激光上皮下角膜切削术(laser assisted sub-epithelial keratectomy,LASEK)前后泪膜稳定性和角膜中央知觉的变化.方法:选择80眼近视眼患者,分别行LASEK和LASIK术,每组40眼,观察患眼术前与术后1个月、3个月及6个月的角膜中央知觉、泪液分泌量(Schirmer 试验)、泪膜破裂时间(break-up time, BUT),并对结果作统计学分析.结果:两种手术术后泪膜稳定性及角膜中央知觉均有不同程度的下降;LASEK术后1个月、3个月角膜中央知觉、术后1个月BUT值与术前相比有显著性差异(P＜0.05);LASIK术后1个月、3个月、6个月角膜中央知觉、术后1个月、3个月BUT值与术前相比有显著性差异(P＜0.05);术后1个月、3个月LASIK和LASEK组间角膜中央知觉、BUT值有显著性差异(P＜0.05),LASIK组角膜中央知觉、BUT值下降更明显;LASIK和LASEK组术后1、3、6个月泪液分泌量分别与术前相比无显著性差异.结论:LASIK和LASEK手术术后均影响泪膜的稳定性与角膜中央知觉,但随着角膜的愈合而逐渐恢复;LASIK对角膜中央知觉、泪膜稳定性的破坏比LASEK更为严重、持久.

Comparison of tear film stability and corneal sensitivity between laser-assisted subepithelial keratectomy with laser in situ keratomileusis?

Objective:To compare the changes in tear film stability and corneal sensitivity after laser-assisted subepithelial keratectomy (LASEK) and laser in situ keratomileusis (LASIK). Methods: Forty eyes of 20 patients underwent LASIK and 40 eyes of 20 patients underwent LASEK to correct mypia. The patients were observed for corneal sensitivity, tear break-up time (BUT) and Schirmer test under local anesthesia before and 1, 3 and 6 months after operation. The results were analyzed statistically. Results: The tear film stability and corneal sensitivity were decreased to some extent in both groups after operation. Compared with before operation, there were significant differences in corneal sensitivity 1, 3 and 6 months after operation and in BUT 1. 3 months after operation in LASIK group (P<0. 05); there were also significant differences in corneal sensitivity 1, 3 months after operation and in BUT 1 month after operation in LASEK group (P<0. 05). The corneal sensitivity and BUT values were obviously different between the 2 groups 1, 3 months after operation (P<0. 05), with the decrease of corneal sensitivity and BUT values more significant in LASIK group. There was no significant changes in Schirmer test results before and after operation in both groups (P>0. 05). Conclusion: Both LASIK and LASEK influence the corneal sensitivity and tear film stability after operation; the influence diminishes with the recovery of the cornea. The influence in LASIK group is more serious and more persistent than that in LASEK group.